RHW and Aquifer Recharge
Managed Aquifer Recharge (MAR), or enhanced recharge, previously known as 'artificial recharge' is the intentional diversion of surface water to the groundwater reservoir by modifying, through a variety of techniques, the natural movement of surface water. The adverse connotations of 'artificial' in a society where community participation in water resources management is becoming increasingly prevalent and important resulted in the development of a more appropriate title: Managed Aquifer Recharge (UNESCO-IHP, 2005).
The main purpose of Managed Aquifer Recharge is to augment groundwater resources by storing excess surface water for later use and restore groundwater levels which may have been depleted due to over-abstraction (UNEP, 1998a), thus enhancing the sustainability of groundwater development. On its own, MAR is not a cure for over exploitation of aquifers and it could merely enhance the rates of abstraction. Consequently, successful and sustainable implementation of MAR projects requires good planning and operation as an integral part of a catchment wide, or national (in SIDS), water management strategy which encourages rainwater harvesting and re-use.
MAR is also employed to address water quality issues, notably rising salinity, by improving the quality of existing groundwater through dilution, as well as removing bacteriological and other impurities from poorer quality surface waters (e.g. treated waste water) through geo-purification and natural attenuation so that it is suitable for re-use (Balke and Zhu, 2008). Groundwater is traditionally preferred as a drinking water over surface water, and so employing MAR techniques to store and then recover poorer quality waters may improve the public perception of recycled water.
Scope of Study
This study was part of the CEHI-UNEP collaboration on promotion of RWH in the Caribbean. The overall aim of this study is to produce a useful and practical guideline for the capture and management of surface water for aquifer recharge in the Caribbean Region, with a particular case study focus on Antigua and Barbuda.
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